138 EDWARD SCHAFER. 
elastic, which are more abundant in the immediate neigh- 
bourhood of the cells, forming, here, in fact, definite layers, 
but some of which pass obliquely across the interspaces and 
connect these layers. ‘The observations here to be recorded 
as to the structure of the capsular envelope are for the most 
part confirmatory of those of Key and Retzius. 
The fibres which lie between the so-called capsules may be 
seen even by the ordinary method of examination, but since 
their general direction is transverse to the long axis of the 
corpuscle they appear mostly as fine dots or granules in the 
fluid (fig. 2), being seen in optical section; by the employ- 
ment of the fine adjustment, however, it may be determined 
that the dotted appearance seen is in reality due to the pre- 
sence of fibres. 
In thin sections of Pacinians which have been prepared 
with chloride of gold the layers of the capsular envelope, at 
least the outermost ones, are readily separable, as shown in Pl. 
1X, fig.4, aa’. Insuch preparations the albuminous fluid be- 
tween the so-called capsules is coagulated, and the membranes 
which bound it are thereby more firmly united, so that when 
an attempt is made to separate the layers the separation 
takes place at the line of the capsules, that is, between the 
two layers of cells of which each so-called capsule is com- 
posed. So that we are able to peel off from the capsular 
envelope layers or tunics which are covered on either surface 
by a stratum of epithelioid cells, the space between these 
strata being occupied by fibres and an albuminous fluid, or, 
in other words, the coats of the Pacinian corpuscle are in 
reality hollow, and composed of the following structures, viz. 
a layer of thin flattened cells bounding them externally; a 
space containing a clear fluid with a greater or less number 
of fine fibres, the latter being chiefly collected near the cells, 
but some extending obliquely across the interspace; and a 
layer of flattened cells bounding the space internally. 
What have hitherto been called the capsules of the Pacinian 
corpuscle are not isolable without rupture of the fibres which 
stretch across the interspaces, and each capsule must there- 
fore be regarded as belonging half to one tunic of the cor- 
puscle and half to another. Sometimes, indeed, as has long 
been known, a cleft containing fluid may here and there 
be seen between the two halves, these being slightly sepa- 
rated from one another. It will therefore be better, in 
future, altogether to discard the term “ capsules ” and to speak 
only of the “ coats” or “ tunics” of the corpuscle, meaning 
thereby the hollow layers, bounded by flattened cells, above 
described; to apply the term capsules to these compound 
